Restriction fragment length polymorphisms (RFLPs) were identified for the structural genes of neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) and adenosine deaminase (ADA). Comparison of variant neuropeptide Y allele frequencies in both normal individuals and patients, that is, schizophrenics and manic-depressives show no significant difference. The linkage relationship between NPY and a putative major locus for manic-depressive illness was examined in two pedigrees. The lod scores obtained under various assumed modes of inheritance suggest absence of linkage. Two restriction enzymes yielded RFLPs at the VIP locus and one enzyme revealed RFLPs in the region of the ADA gene. Association and linkage studies are being conducted using these probes. A rat cDNA clone for calmodulin containing a 900 base pair (bp) insert was isolated from a rat brain Lambdagt11 cDNA library. The cDNA was sequenced and found to encode the COOH terminal half of the calmodulin molecule, that is, residues 74-148. In this region of the molecule the rat, human and frog calmodulins are identical when the deduced rat sequence is used. The nucleotide homology in the coding region between rat and frog is 91% but only limited homology is observed in the 3' untranslated region. Human calmodulin cDNA was isolated from a gt10 cDNA library constructed using cytoplasmic RNA from NTeraD21 cell line. The insert encodes amino acid residues 10-148. The 3' untranslated region was highly homologous to the corresponding sequence in rat. A neurotensin-specific cDNA clone was isolated from a rat brain gt11 cDNA library using a mixed oligonucleotide probe. The cDNA contains an 800 bp insert. Structural analysis of this DNA is now being done.